Field
The disclosed concept relates to electrical apparatus such as, for example, motor starters. The disclosed concept further relates to electrical enclosures for electrical apparatus.
Background Information
Electrical apparatus such as, for example, motor starters are often used to provide protection and control for a load, such as a single-phase or three-phase motor and the like, typically used in, for example, various industrial settings to operate machinery. Safety is a primary concern in the electrical industry. One point of focus relates to electrical safety with respect to uncontrolled arc flash events within motor starters. Arc flash is a dangerous condition associated with the explosive release of energy caused by an electrical arc (e.g., arcing event). This fault can result from many factors including, for example and without limitation, dropped tools, accidental contact with electrical systems, buildup of conductive dust, corrosion, or improper work procedures. A relatively minor event initiated within a motor control center subunit, for example, caused by a flash over to ground, could quickly propagate into a phase-to-phase fault and then a full blown three phase arcing fault, with the arc potentially jumping to the line side of the subunit circuit breaker or fuse.
During the arc flash, the arc gases and debris seek any available path to escape the motor starter. Additionally, pressure is applied to the door of the motor starter, thus causing the door to deform. As a result, during an arc flash event, the arc gases and debris often escape along the perimeter of the door, thereby presenting a serious safety hazard.
There is thus room for improvement in electrical apparatus and in electrical enclosures therefor.